A bag contains $11$ red balls, $8$ green balls, and $10$ blue balls. If a ball is randomly chosen, what is the probability that it is not red?
Answer: There are $11 + 8 + 10 = 29$ balls in the bag. There are $11$ red balls. That means $29 - 11 = 18$ are not red. The probability is $ \frac{18}{29}$.